Usability in Content Pipeline extension

[red-asparagus]

TiledSharp cant be used in Content Pipeline Extension Project as it is don't have empty constructor.

My proposition: add Empty Constructor and make new method that accept filename and works like TmxMap(string filename) constructor.

[marshallward]

Thanks for pointing this out, I have not used the Content Pipeline (from XNA/MonoGame, I assume).

Would multiple constructors work here, one with filename and one without? This would preserve the current API. We can resolve the issues around undefined fields separately.

[red-asparagus]

No problems with non-empty constructor, but method Load() I think need to be public.

[red-asparagus]

Created pull request

#52